XTZ is a new name to this writer and editor, perhaps because
it relies mainly on selling direct to customers. It's a Swedish operation with
such a vast range of models that finding the TUNE
4 on the very complex website proved quite difficult. Fans of the
Muppets' Swedish chef should find the company's problems with the English
language quite entertaining.

If you want your next speakers to be smaller than a breadbox,
XTZ's TUNE 4 speakers are small,
quick to set up, contain their own 'Class D' stereo amplifier in the left
speaker, and have a corresponding app which is 'powered by' (augmented by)
Dirac correction and equalisation software. So the €480/£370 per pair TUNE
4 may well meet the requirements of somebody looking for a stereo
pair with enough bass to infuriate the neighbourhood. XTZ builds a 30 day
returns period into its direct sales, so the purchaser can test the versatile
range of input options and make an informed decision before final commitment.

The speakers look both stylish and cute, with rounded corners
and a finish that looks almost ceramic (but is actually spray-painted MDF). They're designed to fit on a desk, a wall, or really anywhere else one might
desire, and the tweeters are offset to reduce edge reflection effects. Each
speaker is 140mm wide, 252mm tall and 180mm deep, with a 25mm tweeter and a
120mm mid bass cone driver.

Our particular pair came finished in matt white with black
horn-loaded silk dome tweeters and carbon fibre woofer cones; they're also
available matt black. The system is essentially ready to play: with analogue,
digital and Bluetooth inputs and the integrated amplifier, it is incredibly easy
to set up, even for the inexperienced. It took me around ten minutes, much of
that time looking for a replacement mains lead without a Swedish plug. Tried out
in different locations, I tested them on low carpet, a coffee table and a desk,
with various Apps through an iPhone 4S,
and via various input
combinations, and all proved easily optimised. A high-end CD player, a PC and a
smartphone were connected via the
analogue, optical and Bluetooth inputs respectively; from an interface
perspective, these are great loudspeakers.

The system comes with a simple Quick Start Guide, in imperfect
but understandable English, and a remote control that is fashioned from a solid
aluminium block. The remote handset is necessary for changing the source, as the
speakers themselves don't have a button for this (but do display a different
coloured light depending on the selected input). The remote also has the power
button and the amplifier's volume control, so it's a vital part of the
system.

Also included is a 3m cable to join the second speaker to the
amplifier in the first speaker, a 2m optical cable, and a 1.5m (Swedish) mains
lead. Additional hard rubber feet adjust the angle of the loudspeaker, and
pieces of shaped foam can be inserted into the ports on the back of the speakers
to retune the bass alignment usefully as required. The 'master' speaker,
containing the amplifier and all of the inputs is on the left. Indeed,
everything but the Bluetooth connects directly to the rear panel, including the
right speaker. It even includes a USB port that doesn't function as an input
but instead acts as a charger for a Bluetooth device or Chromecast Audio.

Input Options and Sound QualityXTZ has released a free 'powered by Dirac' App, which is
designed to allow the listening experience to be customised. (This is not the
full Dirac software which also includes automated room correction.) Digital
Signal Processing (DSP) can be used to correct measureable issues with the audio
and adjust it based on location and setup. It provides six settings: regardless
of the setting used, the App plays music more quietly than the iPhone
4S's generic Music App or even YouTube, and I found that it did not
sound demonstrably better.

While 'Bass Boost 1' and 'Bass Boost 2' undeniably do
what they say, 'On Desk', 'Bright (2.1)', 'On Wall' and 'Reference' all altered the sound files in a way which may have corrected
the frequency response, but also did so with side effects I did not enjoy, to
the extent that even Apple's own Music App was considered preferable. With the
Dirac equalisation turned off, Apple's Music App plays the same file at a
different volume and with a different sound quality than the XTZ Player; this
was true, even with XTZ's Dirac HD turned off, or in Reference mode.

The iOS XTZ App
will only play files that are actually on the rendering device rather than in iCloud. And if you only own one song from an album, it
refuses to replay it without either having pre-set it to repeat, or starting
another in between. In most situations, a decent tonal balance can be
established with the settings, but we found the sound at its most naturally
dynamic and interesting when no DSP correction at all was applied.

The Windows App version of the Dirac audio processor operated via
the analogue input performs the same way as the iOS App through
Bluetooth: we played CD-quality and high definition sound files through each of
the six settings and found similar results. We also sent a query to the support
team regarding the setup for this version of the App and received a fast and
helpful response. Unfortunately both versions of this App impaired our enjoyment
of the music, no matter which setting was selected, probably due to DSP and code
limitations.

The frequency response corrections cannot be made when used
with an analogue source, as the correction does not take place in the TUNE
4 but at the digital audio source. However, feeding the TUNE
4's analogue input from a high quality CD source provided far
better quality sound, while the most interesting and enjoyable music was found
when playing high definition files via the
optical input. This resulted in a more lifelike and dynamic sound quality, but
still suffered from some mild colorations.

Using the optical connection from a computer proved just as
good as using the analogue input, with high definition files producing an even
more involving experience. This mode of operation also shows that the chosen
music player software has a considerable effect on the sound produced. During
testing, Apple's iTunes sounded
less articulate than either Windows Media
Player or Foobar2000.
The latter in particular sounded tighter with greater natural detail, better
dynamics and superior timing. This clearly audible distinction between players
and Apps does reveal some inherent positive performance capabilities in XTZ's TUNE
4 system.

From an audio perspective, the TUNE
4 shows potential: it improved considerably after running in, and the
bass in particular became freer and more natural. It was then easy to hear the
quality of the file playing and to identify which Apps and settings were being
used.

The plugs to tune the bass ports work well, improving timing
and increasing the clarity across the audio band, while reducing the port thump.
Focus and staging are a strong point and it is capable of presenting
surprisingly good depth perspectives when carefully set up. It has reasonably
high levels of detail and is articulate on speech which can enhance a video
viewing experience over standard desktop speaker fare. It can also work with a
television. Disappointingly, however, music can lack synchronicity across the
stage, resulting in timing anomalies between the bass and the treble. It is
certainly musically competent on a variety of genres even if it does suffer from
some colorations: while this might annoy the aficionado, it is likely to be more
than acceptable in the context of the market segment at which it is aimed.

XTZ recommends adding a subwoofer for increased bass
performance and its range contains suitable matching items, but even when
operating alone, the sound from these little speakers can certainly fill a room
with sound to surprisingly respectable levels. Within its limits it is often
entertaining and can provide an enjoyable musical experience. There is a volume
point above which it starts to clog up fairly rapidly: it also loses detail and
increases in harshness so if you want much higher volume levels, a bigger
speaker will be preferable.

ConclusionsXTZ's TUNE 4 can
impress when provided with good quality material from either digital or analogue
sources, and although colorations are evident, they don't necessarily detract
from the musical enjoyment. However, the XTZ Player App seems to add more
coloration, and this is particularly noticeable when its Dirac equalisation is
employed. Performance is very source dependent, and under our test setup
Bluetooth did show some deficiencies but could well prove adequate for more
casual listening.

As
a neat, easy-to-use desktop speaker and addon to a computer or Bluetooth-enabled
device, it's a usable, wideband stereo system that produces very decent volume
levels. It's reasonably priced at €480 and has a level of finish and style
that makes it visually desirable. The audio itself may not fit perfectly with
our ideals, but the TUNE 4 system
can be fun, charming and genuinely enjoyable.